As a pest control method, there has been known a pest control method including the step of spraying a solution containing a pest control ingredient into open space. As a method for spraying a solution, there has been known a method using, for instance, an atomizing device that atomizes the solution by simultaneously propelling the solution and a propellant (hereinafter, also referred to as “aerosol type atomization method”). However, since the aerosol type atomization method uses a propellant, it is difficult to reduce the size of the atomizing device.
On the other hand, as a method for spraying a solution without using a propellant, there has been proposed a method using an ultrasonic atomizing device in which a vibration plate having a large number of micropores is placed in contact with a piezoelectric vibrator, and voltage is applied to the piezoelectric vibrator for generating ultrasonic vibration at the piezoelectric vibrator to atomize a solution at the micropores of the vibration plate so as to be sprayed (see, for instance, Patent Literature 1).